Welcome to HVAC-Talk.com, a non-DIY site and the ultimate Source for HVAC Information & Knowledge Sharing for the industry professional! Here you can join over 150,000 HVAC Professionals & enthusiasts from around the world discussing all things related to HVAC/R. You are currently viewing as a NON-REGISTERED guest which gives you limited access to view discussions

To gain full access to our forums you must register; for a free account. As a registered Guest you will be able to:

Participate in over 40 different forums and search/browse from nearly 3 million posts.

Trane XV90 "Blower Module"

Talk about service call(s) from hell.

Patient: Trane XV90 -- 2 stage variable speed. Installed in Sep 2002. It's been 90°F+ every day for the past 10 days around here. Nighttime gets down (briefly) to 70-72ish, but then it's 78°F by 8AM. Oppressive humidity (southern Ohio).

Last Friday: come home to a stuffy house. Go out to the condenser, it's running, but blowing out cold air (not hot). Uh-oh. Go inside to furnace -- blower not running, but A/C coil is ice cold. Open unit -- it's a freezer in there. Call service. They say "shut it off" and I do.

Last Saturday: Tech comes out and fiddles. Swaps out 50A61-605 board (you know, the one staring you in the face when you open the panel). Doesn't help. Tells me that the "blower module" is bad and he doesn't have one. Says he'll be back Monday, but don't worry, covered under warranty. In passing, I ask him why this "variable speed" furnace has three speeds:

1. Off
2. When thermostat is set to "On" it fairly quietly runs at a slow speed
3. When the gas valve kicks on (I can hear it) or the AC condenser starts, the furnace turns on to a setting I call "Wind Tunnel". The pitch and whine are the same every time it's running -- I detect no variability whatsoever. And it sounds at least as loud as the 1978 Trane the XV90 replaced. It's not starved for air either -- I installed three additional air intakes (including a second floor one) for this guy.

Tech 1 says, "the dip switches are set wrong." And he flips a couple. Furnace doesn't work -- who knows what good it did?

Last Monday: call the place that sold it and which is "servicing" it. Nice receptionist says, "I just looked at your call -- we're ordering the part." Me: Ordering? When will it be in? Her: "It could take up to 3 days." It was being shipped from 200 miles away. I think, 'how long could that take?' I found out.

Tuesday: Part not in

Wednesday: Part not in

Thursday AM: Part not in

Thursday PM: "Part" (allegedly) appears. Tech on his way.

Different tech from the first guy arrives. Replaces the 50A61-605 (again -- that's the part he brought). Furnace doesn't start. Manages to pull out a black wire which goes into an inline plastic round connector in the harness (I guess he figures I didn't notice -- I'll make him fix it right when he comes back). Nothing runs now, to include the condenser. I disappear, as I just want the goddamned thing to work, and being omnipresent won't improve his or my demeanor. Tech reappears in 10 minutes or so and says "It's the Blower Module. I'll be back at 730AM with one."

So, I'm pretty pissed about this whole affair. Questions are:

1. What's the reliability of a Trane XV90 "Blower Module"? What kind of things cause them to fail? (I find the tech's answer to this was, "chips are all made in China" which is a bull**** answer -- practically no chips are made here in the US) Could a "yearly inspection" have caught this problem?

2. Changing AC to DC is done all the time in the computer power supply I have, but what kind of power are we talking about here with the DC motor in the blower?

3. If this had happened in the dead of January, is there a bypass that can be run to make this work? Tech said there was, but I think, that, too, is bull****. Obviously, this is a concern.

4. How hard to obtain are these "Blower Modules"? I know I can't ask for estimates, but what's does Trane set the MSRP to (can't find them on a Google search, but then I don't know the "real" name of the part)? Would seem that as popular as Tranes are (heck Home Despot sells them) that parts would be widely available. I get stuff ground shipped FedEx in 3 days from California to Ohio. 3 days 200 miles? I think I'm being fed a line.

5. First it takes 3 days to get "the part" and then it's available overnight. Is this standard "Trane" procedure? You know, if it was 80 outside and getting down to 60 at night, I could be more reasonable about waiting. But I'm in a sauna.

6. When the salesdroid sold me this HVAC system, he touted the 2-speed gas valve, and talked up the variable speed. What he said was, "the furnace will run at a slow quiet speed, and will gradually ramp up in speed as the system calls for more and more heat. The two stage gas valve will run in the lower stage until the system really needs to put out more heat." My thermostat in the winter is set for 68 during the day and 60 at night, with a 1 degree tolerance (furnace kicks on at 70). Summer setting is 76. And the furnace either runs at max speed or it's off. 2 degrees of difference at the thermostat wouldn't seem to warrant Wind Tunnel operation every time -- would it? FWIW, my gas bill was about the same (taking into account the increase in Natural Gas prices) before and after the furnace went in. Salesdroid made no promises, and I haven't changed the heat settings.

Now Tech 1 said that the fan should be running "all the time -- never shut it off." Doesn't running it all the time reduce reliability, not to mention waste electricity?

7. Will Trane warranty be covered by any factory-trained Trane tech, or am I locked into the mercy of the Gang Who Couldn't Shoot Straight? Eg, is it still a free warranty service if I call someone else?

I feel like I've been about as patient as I can be for pouring $Forum Rules
plus into this HVAC system that doesn't work for now a week during the hottest spell of the year. I'm fairly cheap -- I try to live without AC, but when it's above 90, I turn on the air.

Once it's fixed, I think I need to discuss the business practices of this company (not a fly-by-night guy -- in 1978 same company installed the "old" Trane the XV90 replaced). Or is it better to call Trane direct and discuss it with them? What do you recommend as the best course of action?

8. When the furnace runs, it condenses water out of the air -- I know because I've seen the water coming out the drain hose in the winter. Tech 1 says that that's normal -- "It's coming from the burner." I thought the burner was sealed and fed with outside air -- I have an intake and exhaust on the side of the house which deal with that. I find it head scratching to believe that water condenses out during the driest season of the year. Is this supposed to happen, and why is it a good thing? I suppose I could get a humidifier, but it seems like I'd be at least partially putting back what the furnace is taking out. Self licking ice cream cone. Put lead into gas so that you can take it out for unleaded gas.

Sorry for the long post. I had held out hope that the second call would be a charm and that the tech would save the day. I was wrong about that, and I'm pretty mad about this whole affair.

1. The blower modules have been very reliable. We've had plenty of problems with the main board, though always in heat mode.

2. Over my head

3. Tech can put in a standard motor

4. Don't know if our A-S/Trane suppliers have them. Our Bryant supplier keeps them in stock. Have replaced a couple on theirs. The factory parts dept will ship overnight if requested.

5. See above

6. There are preset CFM levels but the motor varies the RPM to maintain them as conditions change. As for heating, do you have a single or 2 stage stat? Running the blower constantly is at a very low speed and using very little juice. Really doesn't reduce lifespan as constant operation elimates constant starting & stopping which is also hard on the motor. Constant fan in humid weather keeps the humidity higher in the house though.

7. Other A-S/Trane dealers can service it. If not under a purchased extended warranty, the labor comes from the dealer that sold it however.

8. The secondary heat exchanger drops flue gases below 212 degrees condensing heat from the gases that would be wasted from a less efficient furnace. The water comes from that heat exchanger, not the burners.

A high-efficiency furnace is called a "condensing" furnace for a reason. The condensation is NOT coming from the air in the intake, but rather it is the byproduct from condesing the water vapor produced by burning natrual gas. (There is in fact more water vapor produced than CO or CO2).

Update to the saga. Day 9

Thursday later PM (after I posted): Power went down because of storms. Power down until Friday PM. Waved technician off. Technician agreed to come Saturday morn.

Saturday (Day 8): Technician arrives with what looks like a motor -- disk about 6 inches in diameter with 4 big-ass capacitors I can see on a PCB. Tech installs it on the blower.

Power on -- Nothing, zip, nada. Tech pokes around inside and notes the loose wire he pulled out on Thursday. He reconnects the wire with a wire nut (now a side question -- is there any reason why one would not want to use Scotch-Locks for an electrical connection like this? The blower plenum in front of the motor would seem to be a questionable place to put a wire nut, but that's just me). Anyway, success! The furnace fan now works. Technician seems happy and starts packing up. I go to the window to listen for the howl of the condenser. And I hear birdies, but no condenser. Not so fast ...

Tech goes outside, and jumpers 24V power inside the access panel, and the condenser starts up. Tech pronounces control board (the second one!) bad. He departs with a promise to install one Tuesday morning first thing. As he drives away, I go to the thermostat, and set the cool/heat/off to "Off" and the fan to "Auto". Which should shut off the furnace ... but doesn't. I call the service number to get the guy to come back. Nice lady on the phone tells me to shut off the furnace via the switch at the furnace, as the tech says I've got "a stuck relay" on the "control board."

Fortunately, temps are now down in the 80s in the daytime and low 60s at nite, so I can cool the house. I've had about enough, tho.